Recent questions tagged formal-languages

Write a regular expression for a language over the alphabet {a, b} that accepts all strings starting with 'a' and ending with 'b'.
Answer : Let's dive deep into the regular expression `a(a|b)*b` and understand exactly how it works, component by component. ### The Goal First, let's restate the rule we want to enforce: 1. The string **must** ... Does it end with `b`? No, it ends with `a`. 3. The string is immediately **rejected**....

What is the difference between a Deterministic Finite Automaton (DFA) and a Non-deterministic Finite Automaton (NFA)?
Answer : This is a fundamental concept in computer science, particularly in the theory of computation and compiler design. While they are equivalent in power (they both recognize the same class of languages, called * ... to design an NFA and then convert it to an equivalent, optimized DFA for practical use....